WASHINGTON — Ahmed Abu Khattala, the suspect in the deadly 2012 assault on a U.S. diplomatic post in Libya, was ordered detained indefinitely Wednesday in advance of his prosecution in the attack that killed U.S. Ambassador Christopher Stevens and three other Americans.

The decision by U.S. Magistrate Judge Deborah Robinson was a perfunctory step in an already-unusual journey for the 43-year-old alleged militant who was captured two weeks ago in Benghazi, Libya, and brought to a courtroom a short distance from the U.S. Capitol.

Wearing a green jumpsuit with "prisoner'' emblazoned on the back, Abu Khattala made his second court appearance in five days since arriving in the U.S. He said nothing, other than to acknowledge the operation of a headset transmitting a translation of the proceeding in Arabic.

Michelle Peterson, the suspect's court appointed public defender, did not contest her client's continued detention. But she asserted that the charges presented so far contained an "utter lack of evidence'' of Abu Khattala's involvement in the Sept. 11, 2012, attack.

She also contended that U.S. authorities had falsely attempted to project Abu Khattala as a security threat even though he — along with other U.S. allies — had long fought against the abusive regime of Libyan dictator Moammar Gadhafi.

"The effort to paint him as dangerous… should not be accepted,'' Peterson said.

Federal prosecutors, meanwhile, began outlining their case in broad strokes, alleging that the accused commander in the Ansar al-Sharia militia group was "motivated by his extremist ideology.''

"In the days before the attack, the defendant voiced concern and opposition to the presence of an American facility in Benghazi,'' court documents state.

After the initial assault, prosecutors contend that they can place Abu Khattala inside the ruins of the U.S. compound where he allegedly supervised the seizure of materials and later joined other militia members as they prepared for another assault on the compound's annex building.

"The evidence against the defendant is strong,'' the court documents state. "There are numerous witnesses who support the account…as well as physical evidence.''

Following his capture, while being questioned aboard a U.S. Navy warship, Assistant U.S. Attorney Michael DiLorenzo said Abu Khattala "corroborated'' key information in voluntary statements to authorities.

Peterson told Robinson that she had received "no information'' related to her client's statements during his interrogation.

Before the brief hearing was adjourned, Peterson asked that Abu Khattala be provided a halal diet that conforms to Muslim restrictions and an Arabic-language Quran.